This invention relates to a separable scanning apparatus designed to be incorporated within document guide and recognition equipment for reading of alpha-numeric characters appearing on the face of a document. It constitutes a separable support frame having a surface that is slidably engageable by the document face. A viewing slot is formed through the support frame in communication with the stationary wall surface area. Lenses mounted on the frame focus light reflected through the viewing slot onto light responsive sensors. The apparatus is a self-contained optical scanner, whose components can be prealigned prior to assembly of the support frame within the recognition equipment.
Optical scanning of alpha-numeric characters by use of a transverse scan line to detect light and dark reflective light patterns requires extreme precision in the alignment and focusing of light from the scan line to the receiving light-responsive sensors. Such alignment becomes even more difficult with miniaturization of such equipment in conjunction with the production of compact, economical peripherals. Alignment is also an important factor in servicing of such equipment, since field alignment at the site of the user is impractical where lamps, lenses or light-responsive sensors might have to be replaced.
This disclosure relates to an assembly of character scanning components on a separable subframe or support frame which can be fixedly mounted to a document guiding apparatus or other optical character recognition equipment. The support frame includes a stationary wall surface area adapted to be slidably engaged by the document face. By mounting the components of the character scanning apparatus on this unitary frame, all of the components can be aligned when assembled. A complete aligned assembly can be initially installed in the optical character reader when it is constructed and can be replaced as a prealigned unit for servicing purposes. Such replacement will minimize service and repair time and assures that repaired equipment will meet original alignment specifications.